For one dimensional spectral analysis of the fluorescent properties of kidney microtubules, a vidicon detector has been mounted at the image plane of a microscope. The Princeton Applied Research model 1216/1254 detector is ideally suited for this application in that the scanning parameters of the vidicon are readily adjustable to provide the optimum configuration for the viewed image. However, for initial sample set up, and for two dimensional data collection, the lack of a standard video mode is a limitation. A modification has been made to this detector to produce an optional standard composite video signal. The existing preamplifier in the model 1254 detector is a charge sensitive preamplifier which integrates the video signal across each horizontal scan line. This integration causes a loss of resolution in the horizontal direction, when used in the standard video mode. A fast video preamplifier was designed and placed inside the preamplifier housing with the original preamplifier. A command from the computer terminal selects the scanning mode and connects the proper preamplifier into the system.